64 research outputs found
Eff ect of daily iron supplementation on health in children aged 4–23 months: a systematic review and meta-analysis of randomised controlled trials
Background About 47% of preschool children worldwide are anaemic. Daily oral iron supplementation is a commonly
recommended intervention for treatment and prevention of anaemia, but the effi cacy and safety of iron
supplementation programmes is debated. Thus, we systematically reviewed the evidence for benefi t and safety of
daily iron supplementation in children aged 4–23 months.
Methods We searched Scopus and Medline, from inception to Feb 5, 2013, WHO databases, theses repositories, grey
literature, and references. Randomised controlled trials that assigned children 4–23 months of age to daily oral iron
supplementation versus control were eligible. We calculated mean diff erence (MD) or standard MD (SMD) for
continuous variables, risk ratios for dichotomous data, and rate ratios for rates. We quantifi ed heterogeneity with the
I2 test and synthesised all data with a random-eff ects model. This review is registered with the International
Prospective Register of Systematic Reviews, number CRD42011001208.
Findings Of 9533 citations identifi ed by the search strategy, 49 articles from 35 studies were eligible; these trials
included 42 306 children. Only nine studies were judged to be at low risk of bias. In children receiving iron
supplements, the risk ratio for anaemia was 0·61 (95% CI 0·50–0·74; 17 studies, n=4825), for iron defi ciency was
0·30 (0·15–0·60; nine studies, n=2464), and for iron defi ciency anaemia was 0·14 (0·10–0·22; six studies, n=2145).
We identifi ed no evidence of diff erence in mental (MD 1·65, 95% CI –0·63 to 3·94; six studies, n=1093) or
psychomotor development (1·05, –1·36 to 3·46; six studies, n=1086). We noted no signifi cant diff erences in fi nal
length or length-for-age, or fi nal weight or weight-for-age. Children randomised to iron had slightly lesser length
(SMD –0·83, –1·53 to –0·12; eight studies, n=868) and weight gain (–1·12, –1·19 to –0·33) over the course of the
studies. Vomiting (risk ratio 1·38, 95% CI 1·10–1·73) and fever (1·16, 1·02–1·31) were more prevalent in children
receiving iron.
Interpretation In children aged 4–23 months, daily iron supplementation eff ectively reduces anaemia. However, the
adverse eff ect profi le of iron supplements and eff ects on development and growth are uncertain. Adequately powered
trials are needed to establish the non-haematological benefi ts and risks from iron supplementation in this group
Reducing anaemia in low income countries: control of infection is essential.
In settings with high infection burdens, iron interventions for anaemia may be neither safe nor effective. Strategies to tackle the global burden of anaemia must take this into account, argue Sant-Rayn Pasricha and colleagues
A double blind randomised controlled trial comparing standard dose of iron supplementation for pregnant women with two screen-and-treat approaches using hepcidin as a biomarker for ready and safe to receive iron.
BACKGROUND: Until recently, WHO recommended daily iron supplementation for all pregnant women (60Â mg/d iron combined with 400ug/d folic acid) where anaemia rates exceeded 40Â %. Recent studies indicate that this may pose a risk to pregnant women. Therefore, there is a need to explore screen-and-treat options to minimise iron exposure during pregnancy using an overall lower dosage of iron that would achieve equivalent results as being currently recommended by the WHO. However, there is a lack of agreement on how to best assess iron deficiency when infections are prevalent. Here, we test the use of hepcidin a peptide hormone and key regulator of iron metabolism, as a potential index for 'safe and ready to receive' iron. DESIGN/METHODS: This is a 3-arm randomised-controlled proof-of-concept trial. We will test the hypothesis that a screen-and-treat approach to iron supplementation using a pre-determined hepcidin cut-off value of <2.5Â ng/ml will achieve similar efficacy in preventing iron deficiency and anaemia at a lower iron dose and hence will improve safety. A sample of 462 pregnant women in rural Gambia will be randomly assigned to receive: a) UNU/UNICEF/WHO international multiple micronutrient preparation (UNIMMAP) containing 60Â mg/d iron (reference arm); b) UNIMMAP containing 60Â mg/d iron but based on a weekly hepcidin screening indicating if iron can be given for the next 7Â days or not; c) or UNIMMAP containing 30Â mg/d iron as in (b) for 12Â weeks in rural Gambia. The study will test if the screen-and-treat approach is non-inferior to the reference arm using the primary endpoint of haemoglobin levels at a non-inferiority margin of 0.5Â g/dl. Secondary outcomes of adverse effects, compliance and the impact of iron supplementation on susceptibility to infections will also be assessed. DISCUSSION: This trial is expected to contribute towards minimising the exposure of pregnant women to iron that may not be needed and therefore potentially harmful. If the evidence in this study shows that the overall lower dosage of iron is non-inferior to 60Â mg/day iron, this may help decrease side-effects, improve compliance and increase safety. The potential for the use of hepcidin for a simple point-of-care (PoC) diagnostic for when it is most safe and effective to give iron may improve maternal health outcomes. TRIAL REGISTRATION: ISRCTN21955180
Iron restriction in sickle cell disease: When less is more
Primum non nocere! Can iron deficiency, an abnormality that causes anemia, benefit people with sickle cell disease (SCD) who already have an anemia? The published literature we review appears to answer this question in the affirmative: basic science considerations, animal model experiments, and noncontrolled clinical observations all suggest a therapeutic potential of iron restriction in SCD. This is because SCD's clinical manifestations are ultimately attributable to the polymerization of hemoglobin S (HbS), a process strongly influenced by intracellular HbS concentration. Even small decrements in HbS concentration greatly reduce polymerization, and iron deficiency lowers erythrocyte hemoglobin concentration. Thus, iron deficiency could improve SCD by changing its clinical features to those of a more benign anemia (i.e., a condition with fewer or no vasoocclusive events). We propose that well-designed clinical studies be implemented to definitively determine whether iron restriction is a safe and effective option in SCD. These investigations are particularly timely now that pharmacologic agents are being developed, which may directly reduce red cell hemoglobin concentrations without the need for phlebotomies to deplete total body iron
Serum Hepcidin Concentrations Decline during Pregnancy and May Identify Iron Deficiency: Analysis of a Longitudinal Pregnancy Cohort in The Gambia.
Background: Antenatal anemia is a risk factor for adverse maternal and fetal outcomes and is prevalent in sub-Saharan Africa. Less than half of antenatal anemia is considered responsive to iron; identifying women in need of iron may help target interventions. Iron absorption is governed by the iron-regulatory hormone hepcidin.Objective: We sought to characterize changes in hepcidin and its associations with indexes of iron stores, erythropoiesis, and inflammation at weeks 14, 20, and 30 of gestation and to assess hepcidin's diagnostic potential as an index of iron deficiency.Methods: We measured hemoglobin and serum hepcidin, ferritin, soluble transferrin receptor (sTfR), and C-reactive protein (CRP) at 14, 20, and 30 wk of gestation in a cohort of 395 Gambian women recruited to a randomized controlled trial. Associations with hepcidin were measured by using linear regression, and hepcidin's diagnostic test accuracy [area under the receiver operating characteristic curve (AUCROC), sensitivity, specificity, cutoffs] for iron deficiency at each time point was analyzed.Results: The prevalence of anemia increased from 34.6% at 14 wk of gestation to 50.0% at 20 wk. Hepcidin concentrations declined between study enrollment and 20 wk, whereas ferritin declined between 20 and 30 wk of gestation. The variations in hepcidin explained by ferritin, sTfR, and CRP declined over pregnancy. The AUCROC values for hepcidin to detect iron deficiency (defined as ferritin <15 μg/L) were 0.86, 0.83, and 0.84 at 14, 20, and 30 wk, respectively. Hepcidin was superior to hemoglobin and sTfR as an indicator of iron deficiency.Conclusions: In Gambian pregnant women, hepcidin appears to be a useful diagnostic test for iron deficiency and may enable the identification of cases for whom iron would be beneficial. Hepcidin suppression in the second trimester suggests a window for optimal timing for antenatal iron interventions. Hemoglobin does not effectively identify iron deficiency in pregnancy. This trial was registered at www.isrctn.com as ISRCTN49285450
Decreased Hepcidin Levels Are Associated with Low Steady-state Hemoglobin in Children With Sickle Cell Disease in Tanzania.
BACKGROUND: The contribution of hepcidin as a regulator of iron metabolism & erythropoiesis on the severity of anemia in sickle cell disease (SCD) remains poorly characterized, especially in Sub-Saharan African populations. The aims of the study were to determine if hepcidin is associated with severity of steady-state anemia in SCD and to investigate factors associated with hepcidin and anemia in SCD. METHODS: Archived samples from 199 Tanzanian children, 56% boys aged 3-18 with laboratory-confirmed SCD were analysed based on recorded averaged steady-state hemoglobin (ASSH) quartiles (lowest vs. highest). Univariable and multivariable logistic regression was used to assess associations with ASSH quartiles. FINDINGS: In univariable analysis, hepcidin <5·5 ng/mL was associated with increased odds of being in the lowest ASSH quartile (OR 2·20; 95%CI 1·2-3·93) but which was limited to girls (OR 4·85, 95%CI 1·79-13·09, p = .046 for interaction). In multivariable analyses including either reticulocyte percentage or erythropoietin, lower hepcidin remained significantly associated with lowest ASSH quartile, although the hepcidin-sex interaction no longer reached statistical significance. No associations with ASSH quartile were observed for markers of inflammation, hemolysis or potential iron markers except for microcytosis, associated with higher ASSH, but which was confounded by reticulocyte percentage and alpha-thalassaemia status. INTERPRETATION: Hepcidin is lower in more severely anaemic children with SCD independent of inflammation or markers of erythropoiesis. FUNDING: Funding sources include The Wellcome Trust (080025, 095009, 094780 & 070114), MRC-UK (MC-A760-5QX00), NIHR Oxford Biomedical Research Centre, and the Bill and Melinda Gates Foundation ("Hepcidin and Iron in Global Health", OPP1055865)
Protocol for a multicentre, parallelgroup, open-label randomised controlled trial comparing ferric carboxymaltose with the standard of care in anaemic Malawian pregnant women: the REVAMP trial
Introduction
Anaemia in pregnancy remains a critical global health problem, affecting 46% of pregnant women in Africa and 49% in Asia. Oral iron therapy requires extended adherence to achieve correction of anaemia and replenishment of iron stores. Ferric carboxymaltose (FCM) is a recently established intravenous iron formulation associated with substantial advantages in safety, speed of delivery and total dose deliverable in a single infusion. We aim to determine whether FCM given once during the second trimester of pregnancy compared with standard oral iron distributed through routine antenatal services is effective and safe for treatment of moderate to severe maternal anaemia in sub-Saharan Africa.
Methods and analysis
The randomized controlled trial of the effect of intravenous iron on anaemia in Malawian pregnant women (REVAMP) is a two-arm confirmatory individually randomised trial set in Blantyre and Zomba districts in Malawi. The trial will randomise 862 women in the second trimester of pregnancy with a capillary haemoglobin concentration below 100.0 g/L. The study comprises two arms: (a) intravenous FCM (20 mg/kg up to 1000 mg) given once at randomisation, and (b) standard of care oral iron (65 mg elemental iron two times per day) for 90 days (or the duration of pregnancy, whichever is shorter) provided according to local healthcare practices. Both arms receive sulfadoxine-pyrimethamine as intermittent preventive treatment in pregnancy. The primary outcome is the prevalence of anaemia (Hb <110.0 g/L) at 36 weeks’ gestation. Secondary outcomes include birth weight, gestation duration and safety outcomes, including clinical malaria, serious perinatal events and postpartum haematologic and health-related outcomes in the mother and child.
Ethics and dissemination
Ethical approval was granted by the Research Ethics Committee (COMREC P.02/18/2357) in Malawi and the Human Research Ethics Committee (WEHI: 18/02), Melbourne, Australia. The protocol is registered with the Australian and New Zealand Clinical Trials Registry. The results will be shared with the local community that enabled the research, and also to the international fora.publishedVersio
Antibodies against the erythroferrone N-terminal domain prevent hepcidin suppression and ameliorate murine thalassemia
Erythroferrone (ERFE) is produced by erythroblasts in response to erythropoietin (EPO) and acts in the liver to prevent hepcidin stimulation by BMP6. Hepcidin suppression allows for the mobilization of iron to the bone marrow for the production of red blood cells. Aberrantly high circulating ERFE in conditions of stress erythropoiesis, such as in patients with β-thalassemia, promotes the tissue iron accumulation that substantially contributes to morbidity in these patients. Here we developed antibodies against ERFE to prevent hepcidin suppression and correct the iron loading phenotype in a mouse model of β-thalassemia (Hbb(th3/+) mice) and used these antibodies as tools to further characterize ERFE’s mechanism of action. We demonstrate that ERFE binds to BMP6 with nanomolar affinity, and binds BMP2 and BMP4 with somewhat weaker affinities. We show that BMP6 binds the N-terminal domain of ERFE, and a polypeptide derived from the N-terminus of ERFE was sufficient to cause hepcidin suppression in Huh7 hepatoma cells and in wildtype mice. Anti-ERFE antibodies targeting the N-terminal domain prevented hepcidin suppression in ERFE-treated Huh7 cells and in EPO-treated mice. Finally, we observed a decrease in splenomegaly and in serum and liver iron in anti-ERFE treated Hbb(th3/+) mice, accompanied by an increase in red blood cells and hemoglobin and decrease in reticulocyte counts. In summary, we demonstrate that ERFE binds BMP6 directly and with high affinity, and that antibodies targeting the Nterminal domain of ERFE that prevent ERFE-BMP6 interactions constitute a potential therapeutic tool for iron-loading anemias
Effects of iron supplements and iron-containing micronutrient powders on the gut microbiome in Bangladeshi infants: a randomized controlled trial
Anemia is highly prevalent globally, especially in young children in low-income countries, where it often overlaps with a high burden of diarrheal disease. Distribution of iron interventions (as supplements or iron-containing multiple micronutrient powders, MNPs) is a key anemia reduction strategy. Small studies in Africa indicate iron may reprofile the gut microbiome towards pathogenic species. We seek to evaluate the safety of iron and MNPs based on their effects on diversity, composition, and function of the gut microbiome in children in rural Bangladesh as part of a large placebo-controlled randomized controlled trial of iron or MNPs given for 3 months (ACTRN12617000660381). In 923 infants, we evaluate the microbiome before, immediately following, and nine months after interventions, using 16S rRNA gene sequencing and shotgun metagenomics in a subset. We identify no increase in diarrhea with either treatment. In our primary analysis, neither iron nor MNPs alter gut microbiome diversity or composition. However, when not adjusting for multiple comparisons, compared to placebo, children receiving iron and MNPs exhibit reductions in commensal species (e.g., Bifidobacterium, Lactobacillus) and increases in potential pathogens, including Clostridium. These increases are most evident in children with baseline iron repletion and are further supported by trend-based statistical analyses
Biological dosimetry after radiosynoviorthesis with rhenium-186 sulphide and erbium-169 citrate
Zur Abschätzung der radiobiologischen Sicherheit des Verfahrens wird in dieser Arbeit die Radiosynoviorthese (RSO) mit Re-186 und Er-169 hinsichtlich biologischer Strahleneffekte untersucht.
Bei 23 Patienten wurde eine RSO mit Rhenium-186-Sulfid- (10 Patienten) oder Erbium-169-Zitratkolloid (13 Patienten) durchgeführt. Das behandelte Gelenk wurde anschließend ruhig gestellt. Bei allen Patienten erfolgte vor und 17–19 Tage (Re-186) bzw. 45–50 Tage (Er-169) nach der RSO eine venöse Blutentnahme. Zur Analyse der Strahlenexposition wurde die Häufigkeit von dizentrischen Chromosomen in Lymphozyten der ersten Zellteilung in vitro bestimmt. Pro Patient wurden mindestens 1000 Zellen vor und nach der RSO untersucht, was nach längerer Einwirkung niederenergetischer Strahlung ausreichend ist, um im bestrahlten Kollektiv die im Rahmen der RSO erwarteten Strahlendosen nachzuweisen. Ergänzend wurde bei den mit Re-186 behandelten Patienten der Aktivitätsabtransport aus dem Gelenk mittels Ganzkörperszintigraphie bestimmt.
In der Untersuchung von insgesamt 47017 Zellen fanden sich vor RSO mit Re-186 bzw. Er-169 40 bzw. 88, danach 59 bzw. 105 dizentrische Chromosomen in Lymphozyten des peripheren Blutes. Eine signifikante Zunahme der dizentrischen Chromosomen nach der RSO zeigte sich nicht. Der Aktivitätsabtransport nach RSO mit Re-186 lag durchschnittlich unter 5 % (unter 3 MBq) und ist damit als gering einzustufen.
Die Ergebnisse der Untersuchung von Chromosomenaberrationen und des Aktivitätsabtransports nach Radiosynoviorthese mit Rhenium-186 und Erbium-169 sprechen für eine geringe Strahlenexposition der Patienten und damit für die Sicherheit des Verfahrens.The aim of the present studies was to investigate the biological radiation effect of radiosynoviorthesis (RSO) with Re-186 and Er-169 in order to evaluate the safety of this procedure.
RSO with rhenium-186 sulfide colloid (10 patients) or erbium-169 citrate colloid (13 patients) was carried out in a total of 23 patients. Afterwards, the treated joint was immobilised for three days using splints. From all patients, blood was drawn immediately before and 17 to 19 days (Re-186) or 45 to 50 days (Er-169) after RSO. To evaluate the radiation dose, the yield of dicentric chromosomes in lymphocytes was determined exclusively in metaphases of the first cell cycle in vitro. At least 1000 cells per patient have been analysed before and after RSO which is sufficient to find potential radiation effects after long-term exposure to low energy radiation such as to expect after RSO. In addition, for Re-186 the activity leakage from the treated joint was measured by whole-body scintigraphy.
In a total of 47017 cells analysed from 46 blood samples, 40 and 88 before and 59 and 105 dicentrics after RSO with Re-186 and Er-169 were found. This showed no statistically significant increase in the number of dicentric chromosomes. The measured average activity leakage of less than 5 % (less than 3 MBq) was considered to be low.
The results of chromosome analysis and activity measurement after RSO prove that this procedure is associated with a low effective dose in treated patients and thus can be considered a safe treatment
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